# Ch 47: WEST Middle Grades Math: Circles

### About This Chapter

## WEST Middle Grades Math: Circles - Chapter Summary

This chapter includes a variety of lessons that demonstrate formulas for working with circles in preparation for the WEST Middle Grades Math exam. Instructors provide examples for finding the radius, area and circumference of circles, semicircles and quarter circles. Specific topics covered in these videos include:

- Identifying the parts of circle
- Examples of central and inscribed angles
- Determining the radius, diameter, area and circumference of a circle
- Finding the perimeter and area of a semicircle
- Calculating area, perimeter and radius of a quarter circle
- Solving word problems that include circles

Our instructors are subject-matter experts who show you how to solve a variety of math problems that include circles. After viewing the short video lessons, you can use the embedded video tags to review problem areas and then test your comprehension through the self-assessment quizzes and end-of-chapter test.

### WEST Middle Grades Math: Circles Chapter Objectives

Washington has replaced the WEST Middle Grades Math examination with a National Evaluation Series (NES) test for this subject area. This test is used to assess the knowledge and skills of those wishing to teach basic math at the middle school level. This computer-based math exam includes 150 multiple-choice questions, and you have 255 minutes to complete it. The questions come from four content areas:

- Number sense and operations
- Algebra and functions
- Measurement and geometry
- Statistics, probability and discrete mathematics

Questions on circles can be found within the measurement and geometry content area, which makes up 25% of the 150 questions on the test as a whole. These questions may ask you to estimate or calculate the perimeter or area of various shapes, including circles. You can get practical experience in solving these types of problems through the self-assessment quizzes at the end of each of the lessons in this chapter.

### 1. Parts of a Circle

After watching this video lesson, you will be able to identify the parts of a circle. You will learn the names of four different parts of a circle along with what each part does for the circle.

### 2. Central and Inscribed Angles: Definitions and Examples

When we're working with circles, there are two key angles to know: central angles and inscribed angles. These angles have a few special theorems, which we'll discuss and practice using in this lesson.

### 3. How to Find the Radius of a Circle: Definition & Formula

In this lesson, you will discover the definition of a radius. You will also learn how to find the radius of a circle using three different formulas based on diameter, circumference, and area.

### 4. How to Find the Diameter of a Circle: Definition, Formula & Example

Learn the definition of the diameter of a circle and how to find it using a simple formula. See some examples, then test your knowledge with a short quiz.

### 5. Circles: Area and Circumference

Understanding how to calculate the area and circumference of circles plays a vital role in some of our everyday functions. They serve as the foundation for operating with three-dimensional figures. Learn more about the area and circumference of circles in this lesson.

### 6. Semicircle: Definition, Perimeter & Area Formulas

In this lesson, you'll discover what a semicircle is. You'll also discover the formulas for perimeter and area that will work on every semicircle. Then, test your knowledge by taking a brief quiz.

### 7. Quarter Circles: Calculating Area, Perimeter & Radius

Watch as we solve problems involving the quarter circle in this video lesson. Learn what quarter circles look like, how to find their area, their perimeter, and their radius.

### 8. Circles in Word Problems

Watch this video lesson to learn how you can solve word problems that involve circles. Learn how the properties of circles make your problem-solving life that much easier and quicker.

### Earning College Credit

Did you know… We have over 200 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

### Transferring credit to the school of your choice

Not sure what college you want to attend yet? Study.com has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

### Other Chapters

Other chapters within the WEST Middle Grades Mathematics (203): Practice & Study Guide course

- WEST Middle Grades Math: Basic Arithmetic Operations
- WEST Middle Grades Math: Solving Math Word Problems
- WEST Middle Grades Math: Properties of Numbers
- WEST Middle Grades Math: Estimating & Rounding
- WEST Middle Grades Math: Number Theory
- WEST Middle Grades Math: Roots & Radical Expressions
- WEST Middle Grades Math: Exponents & Exponential Expressions
- WEST Middle Grades Math: Scientific Notation
- WEST Middle Grades Math: Simplifying Whole Number Expressions
- WEST Middle Grades Math: Integers
- WEST Middle Grades Math: Rational Numbers
- WEST Middle Grades Math: Introduction to Fractions
- WEST Middle Grades Math: Operations with Fractions
- WEST Middle Grades Math: Introduction to Decimals
- WEST Middle Grades Math: Operations with Decimals
- WEST Middle Grades Math: Percents
- WEST Middle Grades Math: Money & Consumer Math
- WEST Middle Grades Math: Number Patterns & Sequences
- WEST Middle Grades Math: Properties of Functions
- WEST Middle Grades Math: Graphing Functions
- WEST Middle Grades Math: Negative Numbers
- WEST Middle Grades Math: Absolute Value
- WEST Middle Grades Math: Inequalities
- WEST Middle Grades Math: Factoring
- WEST Middle Grades Math: Monomials & Polynomials
- WEST Middle Grades Math: Writing Algebraic Expressions
- WEST Middle Grades Math: Basic Algebraic Expressions
- WEST Middle Grades Math: Algebraic Distribution
- WEST Middle Grades Math: Writing & Solving One-Step Equations
- WEST Middle Grades Math: Writing & Solving Two-Step Equations
- WEST Middle Grades Math: Simplifying & Solving Rational Expressions
- WEST Middle Grades Math: The Coordinate Graph
- WEST Middle Grades Math: Linear Equations
- WEST Middle Grades Math: Systems of Linear Equations
- WEST Middle Grades Math: Rates, Ratios & Proportions
- WEST Middle Grades Math: Measurements
- WEST Middle Grades Math: Perimeter & Area
- WEST Middle Grades Math: Polyhedrons & Geometric Solids
- WEST Middle Grades Math: Symmetry, Similarity & Congruence
- WEST Middle Grades Math: Properties of Lines
- WEST Middle Grades Math: Angles
- WEST Middle Grades Math: Triangles
- WEST Middle Grades Math: Triangle Theorems & Proofs
- WEST Middle Grades Math: Similar Polygons
- WEST Middle Grades Math: The Pythagorean Theorem
- WEST Middle Grades Math: Quadrilaterals
- WEST Middle Grades Math: Circular Arcs & Measurement
- WEST Middle Grades Math: Transformations
- WEST Middle Grades Math: Data & Graphs
- WEST Middle Grades Math: Statistics
- WEST Middle Grades Math: Data Collection
- WEST Middle Grades Math: Samples & Populations
- WEST Middle Grades Math: Probability
- WEST Middle Grades Math: Sets
- WEST Middle Grades Mathematics Flashcards